Water is a critical natural resource for which demand is high. In addition to clean water for consumption, there is a need for the conservation of water as demand on available resources continues to grow. As such, products which contribute to the recycling and conservation of water resources are desirable to certain consumers and may be required by legislation.
The washing machine is an appliance that is commonly found in residential and commercial settings and which typically uses water to properly clean e.g., clothes, linens, towels, and other machine washable items. A detergent, generally one that contains surfactants and possibly brighteners as well, is added to the water for cleaning. For certain applications, it can be desirable to recycle the water effluent from a washing machine. More particularly, water from the wash cycle, rinse cycle, or combinations thereof can be recycled by using such water again during the washing cycle.
Grey water refers to the effluent from a washing machine appliance that was used during a cycle in the washing machine. For example, grey water is created during a wash cycle. The water that is used for washing clothes or other articles will eventually come to contain e.g., detergent and other matter released from the clothes during the washing process. Grey water is also created during rinse cycle. Water that is added to the clothes during the rinse cycle will also eventually contain e.g., detergent that is released during the rinse and/or spin process.
While grey water can be reused in the washing cycle of a washing machine appliance, allowance must be made for both the capture of the grey water and adjustment for the detergent already present in the grey water. Some of the detergent that is added for a wash cycle is depleted by e.g., removal when the clothes are taken from the washing machine or otherwise by conversion to other substances as part of the washing process. However, a significant amount of detergent will remain in the grey water. This amount of residual detergent must be considered when determining how much detergent must be added when the grey water is recycled for use in another wash cycle.
Typically, the rinse cycle of a washing machine does not remove all of the detergent used during the wash cycle. Some of the detergent remains on the clothes even after rinsing. Accordingly, when the clothes are worn and then washed again, the detergent present in the clothes can contribute to the amount of detergent present in the water used for washing. When too much detergent is added during a wash cycle, this can further increase the amount of detergent that remains on the clothes. In turn, this can lead to a graying effect on the clothes as the detergent builds up over time, can contribute to a roughness feeling, and potentially may even affect skin allergies. Excess detergent can also cause excess suds which may be undesirably left on the clothes after a wash cycle, cause damage to the washing machine, and/or cause the spin speed to decrease therefore causing the clothes to retain too much water.
Accordingly, a system for the reuse of grey water in a washing machine appliance would be useful. More particularly, a system that can allow for measuring of the amount of detergent in grey water and a determination of the proper amount of detergent for supplementing such grey water would be beneficial. Such a system that can also be used to adjust the amount of detergent added to the water by the clothes or other items being washed would also be particularly useful.